Case stacking apparatus



Nov. 10, 1964 w. DU BROFF CASE STACKING APPARATUS 5 Sheets-Sheet 1 FiledAug. 28, 1961 Nov. 10, 1964 w. DU BROFF 3,155,365

CASE STACKING APPARATUS Filed Aug. 28, 1961 ,3 Sheets-Sheet 2 UnitedStates Patent ce 3,156,365 CASE STAQKING APPARATU Warren Du Erotic, 350Carol Court, Highland Park, Iil. Filed Aug. 28, 1961, Ser. No. 134,489 8Claims. (Cl. 214-6) This invention relates to case stacking apparatus,and, more particularly, to apparatus in which a novel mechanism isemployed for vertically aligning cases.

With the increasing use of pallets, lift trucks, etc., it isadvantageous to stack packages such as cases, cartons, and the like.Thus, the equipment utilized for relocating merchandise can be used tomaximum advantage. The savings that are achieved through efficient useof equipment transporting maximum loads can be lost if the load breaksapart during relocation. In other words, the economies achieved throughcompaction of merchandise can be squandered if the compacted arrangementbecomes disarranged. When cartons are stacked four or six high, a smalloffset of each case relative to the one below can mean a substantialinstability. It is, therefore, of prime importance to have stacked casessubstantially vertically aligned.

Although mechanisms have been proposed for this purpose in the past,they have, for the most part, had too complex a character to render themsuitable for the rough handling usually encountered in a cartonmanipulating environment. The cartons move along conveyors in a store orshipping room and the equipment must necessarily be rugged. When acomplex machine fails to opcrate properly, there is down-time, whichpossibly impedes the entire carton handling operation.

It is, therefore, an object of this invention to provide case handlingapparatus in the nature of a case upstacker which is characterized bysuitable ruggedness yet capable of achieving substantiallyvertically-aligned stacks of cases.

Another object is to provide vertical aligning means in a case upstackerwhere the aligning means initially aligns the cases and threafterretracts a predetermined amount so as to slidably confine the casesduring subsequent movements in stacking.

Still another object is to provide a novel vertical align ment mechanismfor a case upstacker which follows a predetermined program of grippingand thereafter slidably confines stacked cases and which isautomatically adjustable at theconclusion of a given stacking operation.

Other objects and advantages of the invention, both general andspecific, may be seen in the details of construction and operation setdown in this specification.

The invention will be explained in conjunction with the accompanyingdrawing, in which FIG. 1 is a transverse vertical sectional view throughthe preferred form of the improved case stacking apparatus as taken onthe line 1-1 of FIG. 2;

FIG. 2 is a fragmentary horizontal sectional view through the improvedstacker as taken on the line 2-2 of FIG. 1, on a scale enlargethereover;

FIG. 3 is a fragmentary perspective view of parts of the apparatus atthe input end thereof, with the parts in positions changed from thoseappearing in FIG. 1; and

FIG. 4- is another fragmentary perspective view of parts of theapparatus on that side thereof opposite the one appearing in PEG. 3 whenobserved toward the input end of the apparatus.

In the illustration given, and with particular reference to FIG. 1, thenumeral 16 designates generally a frame positioned astride a conveyorgenerally designated 11. The frame 16 is equipped with a verticallyreciprocable carriage 12 which is adapted to elevate a case or carton 13by means of lifting dogs 14. The frame is also 3,156,365 Patented Nov.10, 1964 equipped with holding dogs 15 pivotally mounted as at 16 forsupporting a case 13a in an elevated position as part of the developmentof a stack.

The general operation contemplated here includes the advancement of acase 13 horizontally above the floor 17 and on the conveyor 11. As thecase 13 enters the frame 10, it engages a switch arm 18 whichelectrically couples the carriage motor 19 to a speed reducer 24 Thereducer 29 operates through a bell crank 21 and chain 22 to raise thecarriage 12 and thus the carton 13. As the carton 13 moves upwardly, itengages the holding dogs 15, pivoting them outwardly until the casereaches a position generally corresponding to that designated 13a inF143. 1. Thereupon, the holding dogs 15 snap back to the positions shown(under the influence of springs 15a) to support the case in the position13a and thus permit the now-empty carriage 12 to move downwardly andinto a position for elevating a subsequent case. For this purpose, thelifting dogs 14 are pivotally mounted as at 14a, thereby permitting thedogs to pass by a case in the position designated 13 while the carriage12 is still in the process of being lowered. The chain 22 provides anadvantageous function in that it permits the carriage 12 to descend bygravity so that if a subsequent case were under the carriage, there isno positive force exerted by the motor tending to ram the carriage intothe case accidentally admitted to the frame 10.

The foregoing general description is characteristic of an upstackerwhich is seen in my copending application, Serial No. 741,622, filedJune 12, 1958, and reference may be made thereto for additional detailsof construction and operation not found herein.

The above-mentioned application also discloses a height-sensing devicegenerally designated 23, which is operative, upon the completion of agiven stack, to retract the holding dogs 15 to a position wherein theypermit the completed stack to return with the carriage for issuance fromthe frame 1% The frame 1d is equipped with a pair of guide plates 24 and25 which are arranged generally parallel to the direction of conveyortravel and which are mounted on the frame 1% for movement relative toeach other and in a direction transverse of the direction of conveyortravel. For this purpose, the frame 16 is equipped with sleeve bearings26. The guide plates 24 and 25 are equipped with transversely-extendingrods 27 slidably received within the bearings 26.

Causing the relative movement of the guide sheets 24 and 25 is adouble-acting air cylinder 28 which is pivotally mounted on the frame19. The cylinder 28 is equipped with a piston rod 29 which is pivotallyconnected to an eccentric rod 36 at the outer end thereof. The eccentricrod, at the end opposite its pivotal connection to the piston rod (thatpivotal connection being designated by the numeral 31), is aflixed to avertical shaft 32 which is journaled within the frame 10. Also fixed tothe shaft 32 is a lever arm 33, and it will be appreciated that as thepiston rod 29 is moved relative to the cylinder 28, the lever arm 33will be pivoted. Pivotally secured to the lever arm 33 as at 34, is aconnecting link 35, the link 35, at the other end, being pivotallyconnected to a lever arm 36 which is fixed to a shaft 37. The shaft 37is journaled within side bearings 38 provided as part of the frame 19.Thus, the extension or retraction of the piston rod 29 causes acorresponding rotation of the shaft 37. Pinned to the shaft 37 is alever arm 39 which is pivotally connected to a bracket it? rigidlysecured to the side plate 25. A similar linkage, including elements 35,36', 37', 3? and 40', is provided relative to the guide sheet 24, thelinkage systems for the two side sheets being oppositely arranged sothat the sheets move in opposite directions. In other words, retractionof the piston rod 29 brings the sheets 24- and 25 toward each other,while extension of the piston rod 29 separates the two sheets.

The frame is equipped with a switch 41 engageable by the bell crank 21for reversing the flow of air into the cylinder 23.

It is believed that the mechanism thus far described can be betterunderstood by a brief resume of the operation thereof, and such anexposition follows.

As a case enters the frame 10, as in the position 13, it engages theswitch arm 18. The switch 18, through circuitry not shown, couples themotor 19 to the speed reducer 20, causing rotation of the bell crank 21and elevation of the carriage 12. The switch arm 18 also energizes thecylinder 28 to retract the piston rod 29 and bring the sheets 24 and 25together to a position where the case 13 is clamped therebetween. Atthis position, the cylinder 28 cannot force the side sheets 24 and 25further inwardly. As the elevator crank arm 21 rotates in starting toraise the carriage 12, it contacts the air button 41, which causes thecylinder 28 to reverse, thereby backing olf from the case 13 andpermitting the same to be elevated by the carriage 12.

The degree to which the side sheets back off is limited to apredetermined clearance through the interposition of a latchingmechanism generally designated The mechanism 42 includes a ratchet wheelor cam 43 fixed to the vertical shaft 32 and equipped with ratchet teeth44. Pivotally mounted on the frame it) as by shaft 45 is a pawl 46. Thepawl 46 is biased into locking position with the ratchet teeth 44 bymeans of a spring 4-7. Thus, the extension of the piston rod 29 is ableto space the side sheets 24 and 25 apart only a slight distance greaterthan the spacing they had when gripping the case 13. This permits thesheets 24 and 25 to move toward each other and clamp the case 13,thereby sensing the width and then backing off to provide apredetermined amount of clearance between the sheets 2d and 25 for casesof that size.

When the complete stack is formed, another air button 48 is contacted bythe height sensing mechanism and this actuates the pawl release cylinder49 to rotate the pawl 46 so as to unlatch the ratchet 4-3 and therebyopen the side sheets 24 and 25 to the original setting.

While in the foregoing specification I have set down a detaileddescription of an embodiment of the invention for the purpose ofillustration thereof, many variations in the details herein given may bemade by those skilled in the art without departing from the spirit andscope of the invention.

I claim:

1. In the combination of a case upstacker having a frame carrying avertically reciprocable carriage and holding dogs selectivelypositionable under a case being elevated on said carriage to supportthat case, the improved vertical alignment apparatus comprising a pairof sheets mounted on said frame for coactive movement to define avertical channel for the receipt of superposed cases, means for bringingsaid sheets toward each other from a first spacing and thereafter topartially retract said sheets away from said cases whereby said sheetshave a spacing less than said first spacing, said means being responsiveto the vertical movement of a stack of cases for fully retracting saidsheets to said first spacing.

2. In combination, a frame equipped with a carriage mounted therein forvertical reciprocal movement, means on said frame for moving saidcarriage, lifting dogs on said carriage adapted to support a case in astacking operation, holding dogs pivotally mounted on said frame forselectively receiving and supporting a case elevated by said carriage, apair of coacting, spaced-apart, aligning sheets mounted on said framefor horizontal movement relative to each other, means on said frame formoving said sheets from a first spacing into clamping relation with acase on said carriage, and means operatively associated with said movingmeans for limiting the reverse moving said sheets to a spacing providinga predetermined clearance between the sheets and said case and less thansaid first spacing, said limiting means being operative to maintain theclearance-providing spacing until a plurality of cases have beenstacked.

3. The structure of claim 2 in which said moving means includes acylinder and linkage assembly, said operatively associated meansincluding means on said frame responsive to the upward movement of saidcarriage for permitting said sheets to move from saidclearance-providing spacing to said first spacing.

4. The structure of claim 3 in which said responsive means includesupsettable latch means for restricting said linkage means, and alsoincludes means on said frame responsive to the completion of a stack ofcases for upsetting said latch means.

5. in combination, a frame equipped with a carriage mounted therein forvertical reciprocal movement, means on said frame for moving saidcarriage, lifting dogs on said carriage adapted to support a case in astacking operation, holding dogs pivotally mounted on said frame forselectively receiving and supporting a case elevated by said carriage, aconveyor operatively associated with said frame for sequentiallyadvancing cases into said frame and for sequentially removing casestacks from said frame, a pair of vertically oriented guide sheetsmounted in said frame for movement transverse to the direction ofconveyor travel, power cylinder means on said frame, linkage meansinterconnecting said cylinder means and guide sheets to move said guidesheets relative to each ot er, latch means operatively associated withsaid linkage means for restricting the movement apart of said guidesheets to provide a predetermined clearance for cases being stacked onsaid frame, means on said frame responsive to the entry of a casetherein for raising said carriage and actuating said cylinder to movesaid guide sheets toward each other, and means on said frame responsiveto the raising of said carriage for biasing said latch means to aposition to restrict movement apart of said guide sheets to provide saidpredetermined clearance.

6. structure of claim 5 in which said frame is equipped with meansresponsive to the completion of a stack for unbiasing said latch means.

7. In combination, a frame equipped with a carriage mounted therein forvertical reciprocal movement, means on said frame for moving saidcarriage, lifting dogs on said carriage adapted to support a case in astacking operation, hoiding dogs pivotally mounted on said frame forselectively receiving and supporting a case elevated by said carriage, aconveyor operatively associated with said frame for sequentiallyadvancing cases into said frame and for sequentiaily removing casestacks from said frame, a pair of vertically oriented guide sheetsmounted in said frame for movement transverse to the direction ofconveyor travel, power cylinder means on said frame, linkage meansinterconnecting said cylinder means and guide sheets to move said guidesheets relative to each ot cr, latch means operatively associated withsaid linka e means for restricting the movement apart of said guidesheets to provide a predetermined clearance for cases being stacked onsaid frame, means on said frame responsive to the entry of a casetherein for raising said carriage and actuating said cylinder to movesaid guide sheets toward each other, and means on said frame responsiveto the raising of said carriage for biasing said latch means to aposition to restrict movement apart of said guide sheets to provide saidpredetermined clearance, said linkage means including a bell cranklinkage interconnecting said cylinder with said guide sheets, said latchmeans including a ratchet on said bel crank linkage and a pawlcngageahle with said ratchet.

8. In combination, a frame equipped with a carriage mounted therein forvertical reciprocal movement, means on said frame for moving saidcarriage, lifting dogs on said carriage adapted to support a case in astacking operation, holding dogs pivotally mounted on said frame forselectively receiving and supporting a case elevated by said carriage, apair of coacting, spaced-apart, aligning sheets mounted on said framefor horizontal movement relative to each other, means on said framecoupled to said sheets for horizontally moving said sheets relative toeach other to cause said sheets to grip a case positioned on saidcarriage and thereafter to cause said sheets to retract to release thegrip, and means operatively connected to said coupled means fortemporarily limiting References Cited in the file of this patent UNITEDSTATES PATENTS Campbell Oct. 21, 1958 Russell Aug. 9, 1960

1. IN THE COMBINATION OF A CASE UPSTACKER HAVING A FRAME CARRYING AVERTICALLY RECIPROCABLE CARRIAGE AND HOLDING DOGS SELECTIVELYPOSITIONABLE UNDER A CASE BEING ELEVATED ON SAID CARRIAGE TO SUPPORTTHAT CASE, THE IMPROVED VERTICAL ALIGNMENT APPARATUS COMPRISING A PAIROF SHEETS MOUNTED ON SAID FRAME FOR COACTIVE MOVEMENT TO DEFINE AVERTICAL CHANNEL FOR THE RECEIPT OF SUPERPOSED CASES, MEANS FOR BRINGINGSAID SHEETS TOWARD EACH OTHER FROM A FIRST SPACING AND THEREAFTER TOPARTIALLY RETRACT SAID SHEETS AWAY FROM SAID CASES WHEREBY SAID SHEETSHAVE A SPACING LESS THAN FIRST SPACING, SAID MEANS BEING RESPONSIVE TOTHE VERTICAL MOVEMENT OF A STACK OF CASES FOR FULLY RETRACTING SAIDSHEETS TO SAID FIRST SPACING.